ISWEC: energy from the sea

We are producing electricity from wave power for offshore plants and coastal communities.


Wave energy is seen as the largest untapped source of renewable energy on the planet: ENEA and RSE have calculated that if this could be fully harnessed, we could obtain 2 TeraWatts of energy, around 18 trillion kilowatt hours per year, almost equal to the entire world’s annual electricity demand. Moreover, wave energy is predictable, more regulated and constant than other renewable sources. Our ISWEC system does exactly that: it converts the energy of ocean waves into electrical energy, making this immediately available for off-shore plants or feeding it directly into the electricity grid to provide power to coastal communities. The full name of this system is the Inertial Sea Wave Energy Converter , and we developed it in collaboration with Wave for Energy S.r.l, a spin-off of the Politecnico di Torino. The system consists of a sealed floating hull containing a pair of gyroscopic systems , connected to two generators. The waves cause the unit to pitch; it is anchored to the ocean floor, but free to move and oscillate. This pitching movement is intercepted by the two gyroscopic systems which are connected to the generators, and these in turn transform this movement into electrical energy. A simple solution, with cutting-edge technology at its heart. Besides waves, there are many other ways the sea can provide clean energy.

To study and make the most of all the potential of seas and oceans, in collaboration with the Polytechnic of Turin, we have created MORE (Marine Offshore Renewable Energy Lab), a laboratory given over entirely to creating technologies to exploit not just waves, but also ocean currents, tides and the salinity gradient, as well as to improve wind and solar offshore.

Our commitment to the development of the renewable marine energies sector has been further reinforced by joining, as lead partner, Ocean Energy Europe (OEE), the largest European network for the development of ocean energies. This position allows us to collaborate to chart the strategic course of OEE with the aim of commercialising marine technological solutions.


ISWEC is perfect for supplying electricity to off-shore plants, and to Oil & Gas platforms in particular. The first pilot plant is already active in Ravenna, and is connected to our PC80 platform and integrated with a photovoltaic system. This type of application increases the energy self-sufficiency of offshore structures that are located away from the coast, and perhaps in geographical contexts where an electricity supply cannot be taken for granted. This first version has succeeded in producing 105% of its nominal power of 50 kW, but we are working on an industrial model of ISWEC that will bring together all the innovations the MORE Lab is studying. Our goal is 118 industrial ISWEC plants, to arrive at production of about 12 MW of electricity from wave motion. Each of these devices will reach 100 kW at peak and the first opening is planned for the end of 2022. It will be the first plant ever linked up to the Prezioso plant, which produces off the coast of GelaISWEC technology has been deployed in industry thanks to an agreement between Eni, Cassa Depositi e Prestiti, Fincantieri and Terna, which are all putting their skills in their fields to use producing ISWEC plants on an industrial scale. These will provide renewable energy to medium-to-large offshore platforms and settlements on small islands.

Uomo che osserva il supercomputer HPC5

SUPERFAST#3 - Goal: clean energy

Technological challenge

Wave energy is the most constant of all renewable energy types: unlike the sun and the wind, the sea never stays still. In addition, it is also the most "dense", as it consists of nothing more than the concentration of energy produced by the wind, which in turn concentrates the energy produced by the heating of the atmosphere (by the sun). The average energy power obtainable from waves is around 2-3 kW per square metre, four to five times that of wind power and up to twenty times that of photovoltaics. During the development of this technology, we encountered two major issues: corrosion due to the salt in the water, and variations in wave intensity. We succeeded in resolving both of these with ISWEC - first and foremost, the delicate and moving parts are inside the sealed hull, and as such, completely isolated from the salt water, and secondly, the gyroscopic systems that feed the two generators are automatically calibrated in order to respond to varying weather and sea conditions. ISWEC converts wave motion into electricity with an inertial system based on the classic law in physics of conservation of angular momentum:  waves cause the hull to pitch and the movement is transmitted to a gyroscope rotating on an axis perpendicular to the pitching, which produces a third motion, perpendicular to both, that generates electricity. ISWEC has an active role in the energy capture process, which is calibrated by the gyroscope’s rotation speed and lets the hull’s inertia adapt to the marine wavelength that affects it; this feature, implemented for the first time in the world by Eni on an industrial prototype, is what significantly differentiates it from other capture systems. Indeed, it is possible to vary the device’s inertia just as if we were changing its size, thereby obtaining a virtual variable geometry system. Waves are the largest untapped renewable energy source, have high predictability, low variability and extremely high energy density, and wave energy is the renewable source closest to fossil fuels in terms of advantages. These characteristics make waves a promising resource of energy for the future, and a valuable means of achieving decarbonization in off-shore O&G activities, not to mention making small islands energy-independent.

Piattaforma Iswec

ISWEC - The energy that comes from the sea | Eni Video Channel

Industrial integration

ISWEC is an example of the teamwork that lies behind all of our proprietary technology. In this instance, one of the most complex technological challenges to be overcome was the calibration of the gyroscopic system in order to optimise the response of the latter to local sea conditions. This was a fundamental step in taking full advantage of the constant availability that is the most significant feature of wave energy. Here, the task was to analyse and cross-reference large amounts of data from different sources, both meteorological data and information relating to the operation of the machine. HPC4 and HPC5, our supercomputers, provided the assistance we needed: thanks to their computing power, we use advanced mathematical models to develop answer formulas suited to every situation. And so today, the "Cradle of Energy" never stops, guaranteeing constant production levels. ISWEC technology has evolved further with the installation of solar panels on the roofs of the industrial-scale plants which, at 23 metres by 19, offer a large useful surface. Furthermore, the integration between our people and facilities and the MORE Lab is particularly deep and many-faceted. The laboratory is actually based at the polytechnic and relies on the Department of Mechanical and Aerospace Engineering’s research infrastructure combined with two of our important research assets: the Marine Virtual Lab at the Green Data Center in Ferrera Erbognone, which uses the HPC5 supercomputer, and the test area offshore of Ravenna, where we are testing the pilot version of ISWEC. The MORE Lab also forms a network with the polytechnic’s test site at Pantelleria, where other aspects of this technology are studied within an island ecosystem with a view to energy autonomy and no impact on the landscape. At full capacity, the laboratory employs about 50 researchers to collaborate with our people, to quickly get more specific knowledge and put technologies into industrial use. The centre also has a naval test tank and state-of-the-art laboratories. Furthermore, a chair in Sea Energy has been set up, so engineers can be trained to specialise in the new technologies created at the laboratory itself. 


Offshore life - On the Garibaldi C | Eni Video Channel

Wave energy is the largest untapped renewable energy source. Highly predictable with low variability and high energy density, it is the renewable source closet to fossil fuels in terms of advantages, making it particularly promising for the decarbonization of offshore O&G activities

Andrea Alessi, R&D project manager for Marine Energy

Environmental impact

Although different from one another in many ways, all coastal towns and villages share similar characteristics, as they have similar needs. A small inhabited island is not so different from an Oil & Gas platform: their horizons and the challenge posed by distance are the same for both.  For this reason, we are assessing the various possible applications of ISWEC for the supply of electricity to communities on small islands. We are reaching this achievement thanks to agreements with Cassa Depositi e Prestiti, Fincantieri and Terna, to produce and launch versions of ISWEC on an industrial scale. Under these agreements, Fincantieri shares its skills in ship building and Terna its skills in electrical engineering. Cassa Depositi e Prestiti, for its part, works with the partners to handle relationships with central government and local bodies. It also chooses the best financial people for the job and salaries for producing the energy.


Keep in touch

Sign up to receive updates from Eni.